Hypochlorite-comprising compositions for improved mildness to the skin

ABSTRACT

Hypochlorite-comprising cleaning compositions which have improved mildness to the skin which comprise a combination of an amine-oxide and an alkyl sulfate surfactant. The hypochlorite-containing compositions also contain a fatty acid, and may contain additional ingredients including additional detersive surfactants. The compositions preferably have a pH of at least about 12.

FIELD OF THE INVENTION

The present invention is related to hypochlorite-based compositions.

BACKGROUND OF THE INVENTION

The present invention relates to hypochlorite-comprising compositions.It is highly desirable to incorporate hypochlorite in detergentcompositions for bleaching. However, hypochlorite is an irritant andmany consumers suffer from skin irritation when using such compositions.

Particularly, the hands of the user are prone to such irritation. As aresult of coming into contact with such compositions the hands sufferfrom dryness and from a feeling of tightness. This occurs when thecompositions are used neat and also when used in diluted form.

It is believed that hypochlorite attacks the uppermost layer of theepidermal of the skin. This results in the decrease of the elasticity ofthe skin. The skin also becomes more sensitive, resulting in dryness andcoarseness of the skin. In addition the skin may become inflamed andbecome red and sore and itchy. These effects are magnified in alkalineconditions, because alkali is also an irritant. Alkalinity is requiredfor hypochlorite stability and it thus the preferred condition forhypochlorite-comprising compositions. However, alkaline conditionscontribute to skin tightening because it alters the natural pH of theskin.

The object of the present invention is to improve skin mildness andreduce skin irritation of hypochlorite-comprising compositions.

The present invention overcomes these problems by the use of thecombination of amine oxides and specific alkyl sulphates inhypochlorite-comprising compositions. It is believed that thissurfactant combination wets the skin and provides a protective layeragainst hypochlorite and alkalinity on the skin.

Amine oxides and alkyl sulphates are known in the art. U.S. Pat. No.4,282,109 discloses a thickened bleach composition comprisinghypochlorite and a thickening amount of a surfactant blend, comprisingamine oxide C₁₀ -C₁₈ and alkyl sulphate C₈ -C₁₂. There is no mention ofthe reduction of hypochlorite related skin irritation of thesecompositions.

EP 274 885 discloses thickened bleaching compositions comprising alkalimetal hypochlorite and straight chain C₁₄ amine oxide with a mixture ofbranched and straight chain C₁₅ amine oxide. There is no mention ofshort chain surfactants or the reduction of hypochlorite related skinirritation.

EP 233 666 discloses a process for the manufacture of a thickenedbleaching compositions comprising hypochlorite, a hypochlorite-solublesurfactant, including amine oxide and an alkali metal salt of a fattyacid. There is no mention of the reduction of hypochlorite related skinirritation.

DE 28 37 880 covers bleaching compositions comprising alkali metalhypochlorite and mixtures of branched and linear amine oxides of varyingchain length, (C₅ -C₁₇) for increased viscosity. There is no mention ofother long or short chain surfactants or the reduction of hypochloriteskin irritation.

EP 30 401 covers thickened bleaching compositions comprisinghypochlorite and a certain number of product characteristics includingpH and viscosity. Mixtures of C₈ -C₁₈ amine oxides and fatty acids arepreferred as thickening agents. No other surfactants are disclosed.There is also no mention of reducing the irritation effects due to thehypochlorite.

Co-pending European application Nos. 93202187.6 and 93202186.8 discloseshort chain surfactants.

SUMMARY OF THE INVENTION

The present invention is the use of the combination of an amine oxidewith an alkyl sulphate in hypochlorite-comprising compositions forimproved skin mildness. Said amine oxide is according to the formula R₁R₂ R₃ NO, wherein R₁ is a C₈ to C₁₈ alkyl group and R₂ and R₃ areindependently C₁ to C₃ alkyl groups. Said alkyl sulphate is according tothe formula R₄ OSO₃ H, wherein R₄ is a C₆ to C₁₀ alkyl group.

All amounts, ratios, percentages and parts herein are given as a %weight of the total composition unless otherwise stated.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is the use of the combination of an amine oxideand an alkyl sulphate in hypochlorite-comprising compositions forimproved skin mildness.

Thus, an essential ingredient in the present invention is hypochlorite.Preferably the hypochlorite is an alkali metal hypochlorite. Althoughalkali metal hypochlorites are preferred other hypochlorite compoundsmay also be used herein and can be selected from calcium and magnesiumhypochlorite. According to the present invention the compositionscomprise said hypochlorite compound such that the content of activechlorine in the composition is from 0.4% to 5%, preferably from 1% to4%, most preferably from 1% to 3%.

Another essential ingredient is a combination of an amine oxide with analkyl sulphate to improve skin mildness of the composition. Said amineoxide is according to the formula R₁ R₂ R₃ NO, wherein R₁ is a C₈ to C₁₈alkyl group and R₂ and R₃ are independently C₁ to C₃ alkyl groups.Preferably R₁ is a C₁₀ -C₁₈, more preferably C₁₂ -C₁₈ alkyl group and R₂and R₃ are preferably independently C₁ -C₃, more preferably C₁ -C₂ alkylgroups. In the present invention the composition comprises from 1% to5%, more preferably from 1.5% to 4.5%, most preferably from 2% to 4% ofsaid amine oxide and mixtures thereof.

Said alkyl sulphate is according to the formula R₄ OSO₃ H, wherein R₄ isa C₆ to C₁₀, preferably a C₇ -C₉, more preferably a C₈ alkyl group.According to the present invention the composition comprises from 1% to8%, more preferably from 1.5% to 7.5%, most preferably from 2% to 7% ofsaid alkyl sulphate and mixtures thereof.

According to the present invention the compositions may further comprisea number of additional ingredients. Suitable optional ingredientsinclude other hypochlorite-compatible long chain surface activesincluding alkyl sarcosinates, alkyl ether sulphates, paraffinsulphonates and amine oxides.

Another optional component of the present invention is an alkali metalsalt of a C₈ -C₁₈ fatty acid. Suitable fatty acids for use herein can beany C₈ -C₁₈ fatty acid, preferably fully saturated, preferably a sodium,potassium or lithium salt, more preferably the sodium salt.

In a highly preferred embodiment of the present invention thecompositions have a pH greater than 10, preferably greater than 11, morepreferably greater than 12. This is achieved by the addition of from0.8% to 1.5% of a caustic alkali. Suitable caustic alkalis for useherein include sodium and potassium hydroxide.

According to the present invention the composition may also comprise anumber of other additional ingredients such as hypochlorite stable andsoluble colourants, perfumes and hydrotopes such as sodium xylenesulphonate.

According to the present invention the compositions are prepared bymethods known in the art such as those described in GB 1 329 086.

According to the present invention the compositons may be used for avariety of purposes, such as bleaching and hard surfaces cleaning.

According to the present invention the compositions can be illustratedby the following examples.

EXAMPLES

    ______________________________________                                        EXAMPLE       1      2       3     4     5                                    % weight      %      %       %     %     %                                    ______________________________________                                        Ingredients:                                                                  Coconut dimethyl amine                                                                      0.6    0.8     1     0.6   0.6                                  oxide                                                                         Tetra decyldimethyl                                                                         3      3       3     4     2                                    amine oxide**                                                                 Octyl alkyl sulphate                                                                        3      3       3     4     3                                    Coconut fatty acid***                                                                       0.9    0.5     0.5   0.5                                        Sodium hypochlorite                                                                         1.7    1.4     1.4   1.4   1.7                                  Sodium hydroxide                                                                            1      1       1     1     1.3                                  Silicate      0.4    0.04    0.04  0.04  0.4                                  Perfume mixture                                                                             0.3    0.3     0.3   --    --                                   Minors                                                                        Viscosity (cps at. 25° C.                                                            300    420     500   1000  25                                   pH            13     13      13    13    13                                   ______________________________________                                        EXAMPLE       6      7       8     9     10                                   % weight      %      %       %     %     %                                    ______________________________________                                        Ingredients:                                                                  Coconut dimethyl amine                                                                      0.6    0.6     0.6   0.6   0.6                                  oxide                                                                         Tetra decyldimethyl                                                                         2      1       --    4     4                                    amine oxide**                                                                 Octyl alkyl sulphate                                                                        2      1       1     4     5                                    Coconut fatty acid***                                                                       0.9    0.9     0.5   0.5                                        Sodium hypochlorite                                                                         1.4    1.4     1.4   1.4   2                                    Sodium hydroxide                                                                            1.1    1.1     1.1   1.1   1.3                                  Silicate      0.4    0.4     0.4   0.4   0.4                                  Perfume mixture                                                                             0.25   0.25    0.25  0.3   0.25                                 Minors                                                                        Viscosity (cps at 25° C.                                                             280    200     20    500   30                                   pH            13     13      13    13    13                                   ______________________________________                                        EXAMPLE       11     12      13    14                                         % weight      %      %       %     %                                          ______________________________________                                        Ingredients                                                                   Coconut dimethyl amine                                                                      1      1       1     1                                          oxide                                                                         Tetra decyldimethyl                                                                         2      2       2     2                                          amine oxide**                                                                 Octyl alkyl sulphate                                                                        4      5       6     7                                          Coconut fatty acid***                                                         Sodium hypochlorite                                                                         1.7    1.7     1.7   1.7                                        Sodium hydroxide                                                                            1      1       1     1                                          Silicate      0.04   0.04    0.04  0.04                                       Perfume mixture                                                                             0.3    0.3     0.3   0.3                                        Minors                                                                        Viscosity (cps at 25° C.                                                             15     15      15    15                                         pH            13     13      13    13                                         ______________________________________                                         * Hoechst raw material containing the following chain length distribution     C10 and lower 2% max, C12 62%-75%, C14 21%-30%, C16 C18 8% maximum.           ** Akzo raw material containing the following chain length distribution:      C12 2%, C14 97%, C16 1%.                                                      ***Unichema raw material containing the following chain length                distribution: C8-C10 1.5%, C12 53%, C14 24%, C16 14%, C18 7.5%.          

I claim:
 1. A cleaning composition having reduced skin irritation,comprising:a) a hypochlorite compound wherein the amount of activechlorine is from about 0.4% to about 5% of the composition; b) from 2%to about 5% of an amine oxide having the formula:

    R.sub.1 R.sub.2 R.sub.3 NO

wherein R₁ is C₈ -C₁₈ alkyl; R₂ and R₃ are each independently C₁ -C₃alkyl; c) from about 1% to about 8% of an alkyl sulfate having theformula:

    R.sub.4 OSO.sub.3 H

wherein R₄ is C₆ -C₁₀ alkyl; d) from about 0.5% to about 0.9% of analkali metal salt of a C₈ -C₁₈ fatty acid; and e) the balance carriersand adjunct ingredients.
 2. A composition according to claim 1 whereinR₁ is C₁₀ -C₁₂ alkyl, R₂ and R₃ are each methyl.
 3. A compositionaccording to claim 1 wherein R₄ is C₇ -C₉ alkyl.
 4. A compositionaccording to claim 1 wherein said hypochlorite compound is sodiumhypochlorite.
 5. A composition according to claim 1 wherein the pH ofsaid composition is at least about
 12. 6. A composition according toclaim 1 further comprising detersive surfactants, said surfactants areselected from the group consisting of alkyl sarcosinates, alkyl ethersulphates, paraffin sulphonates, and mixtures thereof.